At least some known biological filters include a tank that includes a plurality of media positioned therein. The media is mixed with an amount of water contained within the tank. During a filtering mode, an amount of unfiltered water is channeled into the tank through a strainer such that the water is channeled over and through the media to facilitate trapping particulate matter within the media. During a cleaning mode, the flow of water is reversed such that an amount of water is used to agitate and stir the media. The dirt trapped within the media is released and mixes with the water to form a dirty water mixture that is channeled towards an exit waste line located at the top of the tank. In some known biological filters, during the cleaning mode, the media may gather near the exit at the top of the tank and begin to pack. As a result, a substantial amount of time, water and energy may be required to flush out the dirty water from the tank.
Some known filters may include a second exit to facilitate preventing the media from gathering near the first exit located at the top of the tank. Such second exits may include a drain assembly that is coupled to the wall of the tank to facilitate preventing the media from gathering near either of the exits. Such drain assemblies, however, facilitate increasing manufacturing and maintenance costs.